Disposable plastic container and cover

ABSTRACT

A disposable plastic container and cover wherein the container has an upwardly and outwardly flaring side wall and a rolled rim at the top. The container has an external lower shoulder in the side wall spaced below the rim and an undercut portion that joins the rim region with the external shoulder. An inwardly concave wall section joins the crown of the rim with the top of the undercut portion. The lid includes a bead which engages the undercut portion of the container and an upwardly and outwardly inclined upper inner shoulder which forms a seat for the bead of an identical lid when stacked on it. The upwardly and outwardly extending lid shoulder gives a low stack height to a lid stack, it cooperates with the inwardly concave face of the container side wall for a proper lid fit, and it centers the lid with the adjacent lid when nested.

nited States atent Davis Dec. 18, 1973 DISPOSABLE PLASTHC CONTAINER AND Att0rney-W0lf, Greenfield and Sacks COVER [75] Inventor: Paul Davis, Swampscott, Mass. [57] ABSTRACT [73] Asslgnee aif i a A disposable plastic container and cover wherein the lmmgton container has an upwardly and outwardly flaring side [22] Filed: Nov. 8, 1971 wall and a rolled rim at the top. The container has an [211 App No 196 567 external lower shoulder in the side wall spaced below the rim and an undercut portion that joins the rim region with the external shoulder. An inwardly concave [52] U.S. Cl. 220/60 R, 220/97 C wall section joins the crown of the rim with the top of [51] lint. Cl B65d 43/10 the undercut portion. The lid includes a bead which [58] Field of Search 220/60 R, 97 F, 97 C engages the undercut portion of the container and an upwardly and outwardly inclined upper inner shoulder [56] References Cited which forms a seat for the bead of an identical lid U t STATES PATENTS when stacked on it. The upwardly and outwardly inclined upper inner shoulder which forms a seat for the $233155? 220/60 R X bead of an identical lid when stacked on it. The up- 3,3s1,s72 5/1968 Holder et al. 220/60 R x Wardly and outwardly extending lid Shoulder gives 8 3,388,827 6/1968 Thanhauser et al. 220/60 R low stack height to a lid stack, it cooperates with the 3,520,441 7/1970 Fitzgerald 220/60 R inwardly concave face of the container side wall for a 3,6l3,938 lO/l97l Westcott 220/60 R X proper lid fit, and it centers the lid with the adjacent Primary Examiner-George E. Lowrance Assistant Examiner-James R. Garrett lid when nested.

4 Claims, 5 Drawing Figures PATENTED DESI 8 i975 FIG. 3

DISPOSABLE PLASTIC CONTAINER AND COVER BACKGROUND This invention relates to thin wall plastic disposable containers and lids and more particularly comprises a new and improved food package composed of a lid and container, each of which has good independent nesting characteristics and which mate together well to form a sealed package.

A variety of criteria must be considered in the design of disposable plastic containers and lids. Among these are the ease of securing the lid to the container, the adequacy of the nesting rings provided in both the con tainer and lid to prevent jamming, the stack height or pitch of nested containers and lids, and the stability of the stacks when nested. Many of these characteristics are interrelated, and the shape of each part of the package directly affects the shape of the other.

Containers of the prior art are customarily provided with a lid seat adjacent its rolled rim, which is undercut so as to retain the lid once snapped in place. Above the undercut it is common to form a shoulder either at or below the crown of the rim, which serves as an upper shoulder to support the lower shoulder of the next upper container when the containers are stacked. If the upper shoulder is or very closely approximates a horizontal configuration, it is difficult to insert the lid into the container mouth to seat its bead on the lid seat. On the other hand, if the upper shoulder is too steep, it will induce container wedging or binding of the lower shoulder of one within the upper shoulder of another so that the nested containers willnot readily separate. Moreover, the shape of the upper shoulder may impose an undesirable shape on the upper shoulder of the mating lid, as the upper shoulders of the container and lid ordinarily lie in very close proximity to one another when assembled.

One important object of this invention is to provide a companion container and lid having upper nesting shoulders which are upwardly and outwardly inclined so that the container upper shoulder serves as a guide for the insertion of a lid in the container mouth, provides a low stack height for nested containers, and provides space for the correspondingly shaped upper shoulder of the lid which in turn creates a low stack height for nested lids, and preserves the proper arrangement of stacked lids in a magazine or other automatic handling equipment.

Another object of the present invention is to provide a specially configured bead at the lid periphery which cooperates with the upper shoulder to assist in reducing the stack height of nested lids and which cooperates with the upper shoulder to assist recovery of proper nesting relationship of adjacent lids when they have become disarranged.

To accomplish these and other objects, the container of this invention includes a lazy S configuration extending from the crown of the rim to the inner edge of the uppernesting shoulder, which serves as a guide for the insertion of a lid, and cooperates with the lid so that its upper shoulder may take a highly desirable form. The upper shoulder of the lid is upwardly and outwardly inclined and extends into the concave portion of the lazy S configuration in the container.

These and other objects and features of the invention will be better understood and appreciated from the following detailed description of one embodiment of container and lid, read in connection with the accompanying drawings.

BRIEF DESCRIPTION CF DRAWINGS FIG. 1 is a side view of a container and lid constructed in accordance with this invention;

FIG. 2 is an enlarged fragmentary cross-sectional view of the top portion of the lid and container in the sealed condition;

FIG. 3 is an enlarged fragmentary cross-sectional view of a pair of containers like that of FIG. I, nested together;

FIG. 4 is an enlarged cross-sectional view of a pair of lids like that of FIG. I, nested together; and 5 FIG. 5 is a view similar to FIG. 4% but showing how the lid configuration promotes proper stacking of lids when they are askew.

The container III and lid 11 of this invention typically are formed of thin sheet plastic material by thermoforming techniques and are designed to be so inexpensive to manufacture that they are disposable. The container includes a bottom wall I2, an upwardly and outwardly extending sidewall 14, and a rim 16. The rim preferably is rolled so that its edge faces the side wall of the container, but that is not essential. Immediately adjacent the rolled rim I6 and in part forming an integral portion of it is a lid seat and nesting ring combination I8 which functions in the manner described in detail below.

The lid seat nesting ring configuration is formed at its bottom with an outwardly extending generally horizontal lower shoulder 20. Shoulder 2t) terminates at its outer edge in an intermediate wall section 24 which is effectively composed of three parts; namely a lower vertical portion 28, an intermediate upwardly and inwardly inclined portion 30, and an upper vertical portion 32.

The rolled rim 16 includes a turned in lower flange 34 and a rolled portion 36 which may be defined by a constant or uniformly changing radius or some other suitable curve. The inner end of the rolled portion 36 merges smoothly with an inner shoulder portion 38 which is also defined by a curve. The two curves (of the rolled portion 36 and inner shoulder 33) merge smoothly with one another as suggested at MI so as to describe a lazy S configuration.

In FIG. 3 two identical containers of the type shown in FIG. II are illustrated in nested relationship. The two containers shown are identified by identical reference characters, but the upper of the two containers is further identified with prime numbers. Thus, in FIG. 3, the lower external shoulder 20 of the upper container It) is shown to rest on the concave wall section or upper shoulder portion 38 of the lower container It). The downwardly and inwardly inclined configuration of the concave wall section 33 provides a stable platform for the lower shoulder 20' of the upper container so that the two are readily separable. The pitch or stack height of the containers is such, that the rims of the adjacent containers lie in widely separated planes so as to enable camming fingers or other separating device found on automatic handling equipment to release the lower container from other stacked above. And the undercut portion 30 of the intermediate wall section 24 increases the space in an axial direction between the rims to further accommodate the cams which separate the containers.

Coverall lid 11 which cooperates with the container to form a closure for it is shown in detail in FIGS. 2, 4 and 5. The lid includes a horizontal diaphragm or closure wall 50 which terminates at its periphery in a bead 52 designed as shown in FIG. 2 to fit within the recess 54 that comprises the lid seat of the container. The lower corner 53 of bead 52 is beveled, as shown in the drawings, for reasons described in detail below. The bead 52 merges into an upwardly and inwardly extending wall 56 which in turn merges into vertical section 58. Above section 58 is upwardly and outwardly inclined wall section 60 which approaches the inclination of the tangent of the upper shoulder 38 of the nesting ring-lid seat combination 18 of the container 10. The wall section 60 in turn terminates in an inverted U- shaped channel 62 that includes inner wall 64, upper horizontal wall 66, and downwardly extending skirt 68. The lower end of skirt 68 may be turned outwardly slightly as suggested at 70. The channel 62 receives and effectively protects the rim 16 of the container when the lid 11 is seated.

When the lid 11 is to be snapped into place on the container mouth as shown in FIG. 2, its bead 52 initially is placed on the upper shoulder 38 of the container, and subsequently it is snapped in place past vertical wall 24 either by the application of a uniform pressure about the diaphragm wall 50 or by the application of a pressure first on one side and then on the other such as is described in detail in copending application, Ser. No. 87,179 filed Nov. 5, 1970 entitled Capping Device For Containers. When snapped in place, the bead 52 comes to rest in the lid seat 54. The diaphragm 50 may or may not reach the horizontal shoulder 20 of the container, as the seal is made by contact between the bead 52 and the vertical portion 28 of the intermediate wall section 24 and/or the upwardly and inwardly inclined section 30 of that wall. There may or may not be additional contact between the container and lid in the vicinity of the rim 16. For example, as shown in FIG. 2, skirt 68 of the lid contacts the outer peripheral edge of the rolled rim 16. In addition, while in the embodiment shown the upper, outer edge of the wall section 60 is spaced from the upper shoulder 38 of the container, contact may be made between those parts of the lid and container to form a supplemental seal.

The inclined wall section 60 and beveled comer 53 of the lid provides several advantages. One advantage is the relatively low stack height which results. As viewed in FIG. 4, corner 53 of upper lid 11' rests on inclined wall section 60 of the lower lid ,when the two lids are nested. Because wall section 60 is inclined, corner 53 is supported deeper within the lid than would otherwise be the case if the wall section 60 were horizontal. As another advantage, the inclined configuration of wall section 60 and beveled corner 53 urge lids when nested together to lie in parallel planes as shown in FIG. 4. Thus, referring to FIG. 5, when the lids become disarranged as shown in that figure, it is evident that section 60 of the lower lid does not impede the shifting of the corner 53 of the upper lid on that section so that two lids may right themselves with respect to one another. If wall section 60 were horizontal, the inner edge of that wall would provide a sharp corner on the inside of the lid which would resist shifting of the next upper lid to an aligned position. With the configuration shown, the beveled corner 53 may slide easily up inclined section so that the two lids may become axially aligned.

This latter advantage is particularly important when the lids are automatically fed by magazines in lid capping equipment. The lids are ordinarily loaded in magazines merely by dropping a stack in place, and the operator does not take the time nor is the time available for him carefully to arrange the various lids in precise axially aligned relationship. With a lid configured as shown, the operator need only shake the magazine, and the inclined wall sections 60 of the lids cooperate with the comers 53 of beads 52 so as to cause the lids to selfalign.

Yet another advantage of the lid configuration shown is that it allows the upper shoulder 38 of the container to take the configuration shown. If upper wall section 60 were horizontally oriented, a recess would have to be provided in the rim structure of the container to accommodate wall section 60 when the container is covered by the lid. That in turn would require upper shoulder 38 to approach a more nearly horizontal configuration, which could impede the capping of lids.

From the foregoing description, it will be appreciated that the lid and container of this invention provide many advantages over the prior art. Because modifications may be made of the embodiments shown without departing from the spirit of this invention, it is not intended that the scope of this patent be limited to the single embodiment illustrated and described. Rather it is intended that the scope of this invention be determined by the appended claims and their equivalents.

What is claimed is:

1. In combination a thin-wall, disposable, plastic container and lid,

said container comprising,

a bottom wall, a side wall joined at its lower peripheral edge to the periphery of said bottom wall, said side wall flaring upwardly and outwardly and terminating in an outwardly curled rim at the top having a top crown portion, I

an external radially outwardly extending shoulder in the side wall disposed below the rim,

a wall section extending upwardly from the outer periphery of the external shoulder toward the crown portion of the rim and forming with said shoulder an inwardly opening peripheral channel dimensioned to receive a lid bead and an outwardly opening peripheral channel immediatley above said inwardly opening channel with the uppermost wall of the outwardly opening channel flaring outwardly and curving upwardly and merging smoothly into the crown portion of the outwardly curled rim at the top of the container to provide an inwardly concave wall portion,

the maximum outer diameter of the external shoulder being less than the maximum diameter of the said concave wall portion whereby when identical containers are nested vertically together, the shoulder of the upper container side wall rests on the concave wall portion of the lower container,

said lid comprising,

a horizontally extending diaphragm,

a bead surrounding the diaphragm and sized to lie below the uppermost wall of the inwardly opening peripheral channel of the container wall section to retain the lid on the container when seated on the rim,

an upwardly and radially outwardly extending wall section above the head,

a portion of inverted U-shaped radial cross section secured to the top of the upwardly and outwardly extending wall section and covering the rim of the container with the outer flange of the inverted U- shaped portion in contacting relation with the curled rim of the container when the lid is seated,

said upwardly and outwardly extending wall section lying closely adjacent the concave wall portion of the container and with the outer edge of that section terminating immediately above the medial section of the concave wall,

the maximum diameter of the lid bead being greater than the diameter of the upwardly and outwardly extending wall section of the lid measured at the inner edge thereof and less than the diameter of said section measured at the outer edge thereof whereby when identical lids are nested, the bead of the upper lid rests on said section of the lower lid.

2. The combination of claim 1 wherein a beveled edge is formed at the bottom of the bead which edge rests on the upwardly and outwardly extending wall section of another lid when identical lids are nested.

3. The combination of claim 1 wherein said container wall section includes a vertical wall portion extending upwardly from the outer periphery of the external shoulder, an upwardly and radially inwardly extending intermediate portion joining the top of the vertical wall portion,

and a second vertical wall portion extending upwardly from the top of the intermediate portion and terminating at its upper end at the lower end of the concave wall section,

said bead of the lid engaging the intermediate section and forming a seal therewith when the lid is seated.

4. A thin-wall, disposable, plastic container as described in claim 3 wherein the rim of the container is rolled so that the edge of the rim faces inwardly toward the side wall.

UNITED STATES PATENT @FFKE CERTlFlQA'lE @F REUHN Patent No, 3, 779,418 Dated Dec. 18, 1973 Inventor(s) ul Davis It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the Abstract, line 12, cancel "The upwardly and outwardly line 13, cancel the entire line; line 14, cancel bead of an identical lid when stacked on it,"

Signed andhsealed this 23rdday of April 19m (SEAL) Attest:

EDWARD 1*I..FLETCHER, JR 0 G o MARSHALL DANN Attesting Officer Commissioner of Patents FORM PO-1050 (10-69) USCOMNPDC 663764569 11 U. 5 GOVERNMENT PRINTING OFFICE: I969 0-306-384, 

1. In combination a thin-wall, disposable, plastic container and lid, said container comprising, a bottom wall, a side wall joined at its lower peripheral edge to the periphery of said bottom wall, said side wall flaring upwardly and outwardly and terminating in an outwardly curled rim at the top, an external radially outwardly extending shoulder in the side wall disposed below the rim, a wall section extending upwardly from the outer periphery of the external shoulder toward the rim and forming with said shoulder an inwardly opening peripheral channel dimensioned to receive a lid bead and an outwardly opening peripheral channel immediatley above said inwardly opening channel with the uppermost wall of the outwardly opening channel flaring outwardly and curving upwardly and merging smoothly into the outwardly curled rim at the top of the container to provide an inwardly concave wall portion, the maximum outer diameter of the external shoulder being less than the maximum diameter of the said concave wall portion whereby when identical containers are nested vertically together, the shoulder of the upper container side wall rests on the concave wall portion of the lower container, said lid comprising, a horizontally extending diaphragm, a bead surrounding the diaphragm and sized to lie below the uppermost wall of the inwardly opening peripheral channel of the container wall section to retain the lid on the container when seated on the rim, an upwardly and radially outwardly extending wall section above the bead, a portion of inverted U-shaped radial cross section secured to the top of the upwardly and outwardly extending wall section and covering the rim of the container with the outer flange of the inverted U-shaped portion in contacting relation with the curled rim of the container when the lid is seated, said upwardly and outwardly extending wall section lying closely adjacent the concave wall portion of the container and with the outer edge of that section terminating immediately above the medial section of the concave wall, the maximum diameter of the lid bead being greater than the diameter of the upwardly and outwardly extending wall section of the lid measured at the inner edge thereof and less than the diameter of said section measured at the outer edge thereof whereby when identical lids are nested, the bead of the upper lid rests on said section of the lower lid.
 2. The combination of claim 1 wherein a beveled edge is formed at the bottom of the bead which edge rests on the upwardly and outwardly extending wall section of another lid when Identical lids are nested.
 3. The combination of claim 1 wherein said container wall section includes a vertical wall portion extending upwardly from the outer periphery of the external shoulder, an upwardly and radially inwardly extending intermediate portion joining the top of the vertical wall portion, and a second vertical wall portion extending upwardly from the top of the intermediate portion and terminating at its upper end at the lower end of the concave wall section, said bead of the lid engaging the intermediate section and forming a seal therewith when the lid is seated.
 4. A thin-wall, disposable, plastic container as described in claim 3 wherein the rim of the container is rolled so that the edge of the rim faces inwardly toward the side wall. 